SIDDT syndrome is a previously undescribed disease that presents with a variety of clinical symptoms including respiratory arrest leading to death by six months of age, ambiguous genitalia, and cranial nerve palsy. The disorder has only been seen in the Old Order Amish population, and is inherited in an autosomal recessive fashion. Historically the syndrome has been unexplained, no diagnostic tests were available, and clinical recognition in the neonate was difficult, particularly in affected females.